Ten minutes after Williams did so, Armstrong ran out of the house naked and soaking wet, lay face down in the middle of the street and declared "I am God," police and neighbors said.
Police said Armstrong killed Williams, 37, a service adviser at Central City Toyota, in West Philadelphia, by beating and strangling him.
Defense attorney Joseph Canuso said a defense psychiatrist had determined that at the time of the killing, Armstrong had a panic attack that rendered him "incapable of forming the specific intent to kill" and that the panic attack had been brought on by Williams' "attempt to have sexual relations" with Armstrong.
Although it has no specific definition, the gay-panic defense typically rests on a defendant's being so shocked by sexual advances from someone of the same gender that he assaults or kills the person. Canuso did not use the term "gay panic" in his arguments.
But Assistant District Attorney Leon Goodman said that what Canuso is pursuing is the "gay panic" defense and that it hasn't been accepted in Pennsylvania.
The defense has successfully been used elsewhere, including in 2008 when an Illinois man was acquitted after stabbing a friend 61 times after a night of drinking.
Yesterday's hearing addressed Goodman's motion to preclude Canuso from pursuing the defense at trial.
"There's a particular danger in that [defense] . . . to state to a jury this defendant did what he did because of a sexual advance by a person of the same sex," Goodman said. "It turns into almost a referendum on . . . a homosexual lifestyle."
Canuso said that his chosen defense is "not a novel theory" and that it's "fodder for trial," not for a pretrial motion. He said Armstrong's bizarre behavior before and after the murder, some of which was caught on video by a neighbor, will also play a role.
Blood tests taken from Armstrong on the night of the slaying revealed that he had not taken PCP after all and that the only substance in his system was cannabis, Goodman said yesterday.
Judge Gwendolyn Bright, who placed a gag order on the case yesterday, is expected to rule on the motion on May 26.